Just checked
Gurman's tweet again and in response to someone asking him about the iMacs yesterday after the Apple Online Store came back online, he responded with "Patience, my friend". Which sounds to me like still stands by his prediction of new iPads
and iMacs this week?
On the other hand, it would really be somewhat unusual for Apple to announce two new products via press announcements at different dates
of the same week, at least I can't recall right now if it happened before. Wouldn't it kinda make more sense to announce them both at the same day of the week at that point, instead of having to take down the website and everything twice in short succession? Unless they maybe want to separate the new iPads and Macs from each other. Either way, as long as the store doesn't go offline again, I'd be very cautious about a second announcement this week.
In any case, whenever it may be, I really hope that the new iMacs are accompanied by an updated MacBook aswell, even if Gurman doesn't mention it. After the release of new iMacs and MacBooks, it would be the first time in years that every Mac in the lineup is less than one year old (except for the Mac Pro/iMac Pro category which we already know will get that long-awaited update later this year). Would be a shame if it's the MacBook that's left behind unupdated this time around.